well, i just would wait until ypur plant is 10 days older ( or a few cm higher ) than now. its enough time to wait until end of week 3.atm she is doing a " rooting job" and i wont disturb her now. If she tends to grow very dense, just rise the lights and she will stretch. But atm everything looks fine and her time for LST will come soon , if she grows nicely and vigor.happy growing